Pressure sensors in fuel injection systems for measuring the fuel pressure are known in the state of the art. Such known pressure sensors are generally arranged in a central pressure accumulator of the injection system where they are subjected to the high pressure of the fuel in the injection system. In modern common rail systems the fuel pressure may be a few thousand bar. The pressure sensors therefore have to be sealed off from the high pressure of the fuel in the injection system and thus constitute an elaborate and cost-intensive component. Furthermore, finding a suitable location at which to fit the pressure sensor is something of a problem in systems having no central pressure accumulator.